/*
 * Copyright (C) 2009 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect;

import com.google.common.base.Preconditions;

/**
 * List returned by {@code ImmutableSortedSet.asList()} when the set isn't
 * empty.
 * 
 * @author Jared Levy
 */
@SuppressWarnings("serial")
final class ImmutableSortedAsList<E> extends RegularImmutableList<E> {
    private final transient ImmutableSortedSet<E> set;

    ImmutableSortedAsList(Object[] array, int offset, int size,
            ImmutableSortedSet<E> set) {
        super(array, offset, size);
        this.set = set;
    }

    // Override contains(), indexOf(), and lastIndexOf() to be O(log N) instead
    // of
    // O(N).

    @Override
    public boolean contains(Object target) {
        return set.indexOf(target) >= 0;
    }

    @Override
    public int indexOf(Object target) {
        return set.indexOf(target);
    }

    @Override
    public int lastIndexOf(Object target) {
        return set.indexOf(target);
    }

    // The returned ImmutableSortedAsList maintains the contains(), indexOf(),
    // and
    // lastIndexOf() performance benefits.
    @Override
    public ImmutableList<E> subList(int fromIndex, int toIndex) {
        Preconditions.checkPositionIndexes(fromIndex, toIndex, size());
        return (fromIndex == toIndex) ? ImmutableList.<E> of()
                : new RegularImmutableSortedSet<E>(array(), set.comparator(),
                        offset() + fromIndex, offset() + toIndex).asList();
    }

    // The ImmutableAsList serialized form has the correct behavior.
    @Override
    Object writeReplace() {
        return new ImmutableAsList.SerializedForm(set);
    }
}
